The event attribute of <f:ajax> can hold at least all supported DOM events of the HTML element which is been generated by the JSF component in question. An easy way to find them all out is to check all on* attribues of the JSF input component of interest in the JSF tag library documentation and then remove the "on" prefix. For example, the <h:inputText> component which renders <input type="text"> lists the following on* attributes (of which I've already removed the "on" prefix so that it ultimately becomes the DOM event type name):

blur

change

click

dblclick

focus

keydown

keypress

keyup

mousedown

mousemove

mouseout

mouseover

mouseup

select

Additionally, JSF has two more special event names for EditableValueHolder and ActionSource components, the real HTML DOM event being rendered depends on the component type:

valueChange (will render as change on text/select inputs and as click on radio/checkbox inputs)

action (will render as click on command links/buttons)

The above two are the default events for the components in question.

Some JSF component libraries have additional customized event names which are generally more specialized kinds of valueChange or action events, such as PrimeFaces <p:ajax> which supports among others tabChange, itemSelect, itemUnselect, dateSelect, page, sort, filter, close, etc depending on the parent <p:xxx> component. You can find them all in the "Ajax Behavior Events" subsection of each component's chapter in PrimeFaces Users Guide.